# monte carlo simulation to get 95% confidence and prediction intervals

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- This topic has 11 replies, 6 voices, and was last updated 9 years, 6 months ago by MBBinWI.

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- July 27, 2010 at 4:56 pm #53535
How do I use monte carlo simulation to get 95% confidence and prediction intervals for my model in linear and multiple regression analysis ?

0July 27, 2010 at 5:15 pm #190509

Robert ButlerParticipant@rbutler**Include @rbutler in your post and this person will**

be notified via email.If you build a regression model you already have an estimate of the confidence intervals for both the overall model as well as the coefficents.

0July 28, 2010 at 2:45 pm #190511yes i know. i mean how do i make use of simulation techniques using monte carlo to get the 95% CI and PI for observation given X1, X2, X3 = given values.

currently i am using statsgraphics but i would like to try out using monte carlo. what are the steps in Minitab using monte carlo ?

0July 29, 2010 at 12:38 pm #190514Though I’ve never used it, Minitab produced a article on the topic. You can find it on Minitab’s website here:

[url=http://www.minitab.com/uploadedFiles/Shared_Resources/Documents/Articles/Monte%20Carlo%20Simulation%]Hope this helps.

0July 30, 2010 at 11:01 am #190522You can build the model using Crystal Ball.You will have data sets for X’s from which you have arrived at the regression equation.For each X data set,identify the data distribution(Green cells-Definition cells) in Crystal Ball.For Y cell put the regression equation in the cell & make it Forecast cell(Blue cell in Crystal Ball).When run the simulation.It takes all the values from the data sets of Xs depending upon the distribution & then plots a prediction grpah for Y.You can play with graph by moving the pointer & having values for different certainty %.

0August 1, 2010 at 1:52 pm #190528hi JHJ, the URL returned a message : Bad Request (Invalid URL).

then i tried

http://www.minitab.com/uploadedFiles/Shared_Resources/Documents/Articles

and it states page not found.0August 1, 2010 at 1:54 pm #190529Thanks Vinayak. But i do not have crystal ball.

anyone familiar with monte carlo using minitab ?0August 1, 2010 at 8:45 pm #190530I think the posting interface limits the amount of characters. You can try to copy and paste the following link into your browser.

http://www.minitab.com/uploadedFiles/Shared_Resources/Documents/Articles/Monte Carlo Simulation Article.pdf

If you see “%20” in the post, be sure to replace all instances with a single space.

0August 1, 2010 at 8:46 pm #190531August 3, 2010 at 11:46 am #190545

PaulonisParticipant@paulonis**Include @paulonis in your post and this person will**

be notified via email.It does not appear that the Minitab article takes into account the uncertainty of the model in predicting the uncertainty of the model output. The article is about performing a sensitivity analysis assuming a perfect model and uncertain inputs. I don’t think it is what the original poster is looking for. The article does, however, describe an approach for using Minitab for a Monte Carlo analysis.

To the original poster, what is the purpose of your question? If you’ve run regression in Minitab, you can analytically generate confidence and prediction intervals for any set of X’s. Why would you want to use a Monte Carlo method?

0August 8, 2010 at 7:04 am #190569i am actually comparing the simulation results taken from statsgraphics to results from using Monte Carlo in Minitab.

I was told that simulation results are done separately for beta0, beta1 etc in the regression equation. However, in monte carlo in mintab, it is able to handle all betas siimultaneously. and thus i would like to try if this is true, and how much the results differ and will there be any visible impact if i have done my analysis in diff softwares.

0August 11, 2010 at 3:12 pm #190589

MBBinWIParticipant@MBBinWI**Include @MBBinWI in your post and this person will**

be notified via email.Then call up Minitab support and talk to their techies. They are very responsive to enquiries on how analyses are being performed.

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